A lot of people in the media seem to want Nokia to fail, but the N900 is in fact highly successful in its market segment. When it was launched, Nokia said Maemo wasn't ready for mass consumption yet, and now say that it is exceeding sales expectations. According to Engadget, it sold 100 000 in the first five weeks, not months.
What Nokia also said is that the next product *will* be ready for mass consumption, so we can safely expect significantly stronger sales based on their surprisingly honest statements about the N900. It does have a real chance of changing the world for GNU/Linux (as opposed to Android/Linux).
And why wasn't the N900 ready for mass consumption? They haven't yet ported 100% of their features from Symbian, and most of the default applications are stuck in landscape mode due to their heritage. Don't trust the mainstream press on this. Despite reporters' bad conclusions about the cause, the UI in general is extremely well designed, and counting the number of apps in the Ovi repository is ridiculous given that the Maemo repository is full of apps.